Proximity wireless communication is a communication method for transmitting and receiving data at high speed over distances of several centimeters to several tens of centimeters. Typical examples of proximity wireless communication methods include Transfer JET and NFC (Near Field Communication). One of the assumed services is file transfers, and there has been a suggested method of smoothly performing bidirectional file transfers.
One of the important applications of the proximity wireless communication is “touch communication.” Two devices are brought close to (in touch with) each other for an extremely short period of time, so as to exchange files. In this case, only an extremely short period of communication time can be secured, and therefore, a file exchange method that effectively uses the limited time is needed.
However, in a case where a subject file to be transferred is held in a hard disk drive (HDD), a delay in accessing the HDD becomes a problem. That is, data is loaded into a memory after a waiting period for seeking, a waiting period for a data transfer, and waiting periods for interrupts by them. The data is then transferred through a proximity wireless interface. In this manner, a file transfer is performed.
If the touching time is one second, several tens of milliseconds to several hundreds of milliseconds are required for loading transmission data into a memory, with the waiting period from seeking of the HDD to the data transfer being taken into account. As a result, in the touching time of one second, the time that can be used for actual proximity wireless communication is greatly reduced.
Furthermore, in a case where the subject file to be transmitted is stored in a network storage for the transmission terminal, another delay occurs. That is, in a case where a network delay occurs in accessing a network HDD, the network delay in accessing the HDD is added to the above mentioned delay in accessing the HDD. Therefore, the time that can be used for actual proximity wireless communication becomes very short.
Particularly, in a use situation, for example, where touch communications are repeated in public places, the accumulation of time loss becomes large, and adversely affects the file transfer efficiency of the entire system.